Study questions: Midterm II (Note: Marine Mammal question not included)

1. Why is the planktonic lifestyle common in the sea? How does the density and viscosity of seawater affect the sizes of animals of plants and herbivores?

2. How does size and speed affect an organism’s ability to move in seawater? Describe Reynold’s number.

3. What are the main variables that determine the sinking rate of plankon? How have plankton solved the sinking problem? Describe organisms that typify four adaptations to reduce density, and three adaptations to increase resistance.

4. Discuss the similarities and differences between adaptation to prevent sinking in plankton and to efficiently swim in fish. What types of resistance are relevant when considering adaptations of plankton versus fish? How do fish and plankton differ in adaptation related to types of resistance?

5. Why is the benthic, sessile suspension feeding strategy found only in aquatic systems? (Try to think of at least 4 reasons)? Name six taxa (class or phyla or common names) in which suspension feeding species occur. What are the differences between active and passive suspension feeding? Give two examples of each. What are the two ways active suspension feeders create currents? What is the Bernouli force and how do suspension feeders use it?

6. How do suspension feeders actually capture particles (5 methods)? Why is simple sieving a rare method of suspension feeding? Explain viscous forces, and boundary layers in terms of Reynold’s number.

7. Why is colonial (modular) construction associated with suspension feeding? Name the phyla/class of some colonial suspension feeders.

8. Define and give an example: sequential hermaphroditic reproduction, simultaneous hermaphrodites, parthenogenesis, and vegetative reproduction.

9. Why is external fertilization so common in marine invertebrates? What are the disadvantages and benefits of external fertilization? Draw a graph: How does fertilization success change with dilution time, and distance from source? What are the disadvantages and benefits of small egg size in marine invertebrates?

10. What strategies do marine animals employ to overcome the disadvantages of external fertilization? What mechanism prevents cross-species fertilization?

11. What is the difference between direct development (viviparous), lecithotrophic larvae, and planktotrophic larvae?  How is egg size associated with different larval feeding modes and dispersal distances? Describe a high investment (per offspring) and a low investment strategy.

12. What are the advantages and disadvantages of larval dispersal? How does larval type affect speciation?

13. Diagram the life cycle of a typical coral, showing sexual and asexual reproduction. Under what conditions should a coral switch from asexual (vegetative) to sexual reproduction?  

14. What are the three major classes of marine fishes? Which is the most diverse? Describe the four types of propulsion.

15. What fish shape would best reduce frictional drag? Form drag? Induced drag? What features or adaptations of the tunas make them efficient sustained swimmers? Why are they called energy speculators?

16. What are the differences between the three buoyancy mechanisms in fish? What are the disadvantages of a gas swim bladder? Of hydrodynamic buoyancy?

17. What are the main differences between cruising and accelertion specialists?

18. I know a fish that is dorsal-ventrally flattened and cryptically colored. Where does it live and how does it swim? What is its foraging life style?

19. I know a fish that is laterally compressed and swims with paired fins. Where does it live and what coloration might it have? What does it eat?

20. I know a fish that is silvery colored and with a deep, narrow tail. What can you guess about its ecology?

21. Give two different examples of high investment (per offspring) reproductive strategies in marine fish. Of low investement. Compare the reproductive strategies of external fertilizing scatterers with that of sharks, using examples.

22. Why are most species of sea turtles are endangered? How does their endangerment relate to their life style and biology?

23. How do sea birds differ, in general, from other birds? In general terms, which types of seabirds have the biggest salt glands? Why do you think seabirds have high investment reproductive strategies, and sometimes have long migration paths?

24. Why do marine birds nest in isolated locations, in colonies? What are the advantages and disadvantages? Why might seabirds that are underwater swimmers be generally more generally have colonies located near the continental shelf and in upwelling zones?